1. Field of the Invention
This invention relates to a polyetherester elastomer composition. In particular, the invention concerns an improved composition formed from a melt blend of specific polyetherester elastomers and to a film produced therefrom. The composition is particularly useful in diaper-leg elastic tapes.
2. Description of the Prior Art
A wide variety of polyetheresters are known, as for example from Witsiepe, U.S. Pat. Nos. 3,651,014, 3,763,109, and 3,766,146, from Hok et al., U.S. Pat. No. 3,932,326, and from Nishimura et al., "Elastomers Based on Polyester", J. Macromol Sci. (Chem.), Al(4), 617-625 (1967). Blends of copolyetheresters also are known, as for example from Schroeder et al., U.S. Pat. No. 3,917,743 and Japanese Patent Application Publication Kokai No. 59-58051. Although the known polyetherester compositions have been introduced heretofore for various purposes, such as for films and fibers, the known compositions have not been as effective as would be desired for certain applications. For example, thin elastic strips or films intended for gluing to the legs of baby diapers have a particularly difficult set of requirements. These requirements include high tenacity, high elongation, low set and high recovery-power per unit weight of film. In addition, such film must be free of excessive blocking in order to permit wide rolls of the film to be unwound without excessive sticking or film distortion. An object of the present invention is to provide an elastomeric composition that when converted into film will more readily meet these requirements than could the compositions of the prior art.